Lawn-mower



(No Model.) I

E.R.STABLER. LAWN MOWER.

Patented May 16, 1893,

UNITED STATES PATENT OFF1cE./

EDWARD R. S'IABLER, OF BRIGHTON, MARYLAND.

LAWN-MOWER.

SPECIFICATION forming part of Letters Patent No. 497,420, dated May 16,1893.

Application filed August as, 1892. Serial No. 448,887. (No modeL) To allwhom it may concern.- mower frame to regulate th height of cut. Be itknown that I, EDWARD R. STABLER, he handle is not shown,it beingimmaterial a citizen of the United States, residing at to anunderstanding of my invention. Brighton, in the county ofMontgomery,State 6 is the fixed knife bar-so called-extendof Maryland,have invented certain new and ing across the machine in proximity to theuseful Improvements in Lawn-Mowers; and path of the revolving cutteredges. It is I do declare the following to be a full, clear, mountedupon pivots 7, journaled or fixed in and exact description of theinvention, such the frame, so as to be capable of free oscillaas willenable others skilled in the artto which tory movement within certainlimits. It is it appertains to make and use the same. held from turningtoo far toward the revolving It is the object of my invention to providecutters by a positive step preferably formed improved cutting devicesfor lawn mowers by the rear endof the previous'revolvingblade whichshallenable the severing of the grass which may be arranged to be in contactwith to be more perfectly performed, shall obviate the end of the fixedblade at the instant the the frequent setting and adjusting of theforward end of thesucceedingblade runs onto fixed knife bar, and shallpermit the knives the extension 18. If the blades'are made on to bereadily sharpened without that exera steep helix so that the precedingblade cancise of care and skill which is ordinarily necnot have thisfunction, a stop may be formed essary to insure a perfect contactbetween by a screw 8 mounted in an car 10 on the 20 the rotary andstationary knives for their frame 1. This screw will notinterfere withthe full length. free action of the fixed blade in maintaining Myimprovement consists in a fixed knife contact with the revolving bladeat all parts i volving blades) adapted to be held by aspring will onlyoperate momentarily at the instant 5- or yielding pressure against therevolving between the leaving of the fixed blade by the blades andprovided with a forward projecpreceding revolving. blade and theencounution extending beyond the edge of the fixed tering of it by thesucceeding revolving blade.

blade and in the direction from which the lat- I however prefer thefirst mentioned construc- 8o ter is approached by the revolving blades.tion in which the preceding blade acts as the o Myimprovement furtherconsists in certain stop, for the reason that it is less apt to getparts and combinations thereof hereinafter out of order or bemisadjusted, and because more particularly set forth and claimed. thecut of the machine will then be continu- In order to make my inventionmore clearly ous. The bar 6 is free to turn in the reverse understood Ihave shown in the accompanydirection, such turning being however resist-5 ing drawings means for'carrying the same ed by springs as hereinaftermore particuinto practical eifect, without however limitlarly described.ing the improvement in its useful appliea-' 11 indicates the bladeof theso called fixed tions to the particular construction which, for knife,mounted upon the bar 6 to which it is the sake of illustration, 1 havedelineated. secured by screws 12. '40 In said drawingsFigure1 is atransverse 'The springs, by which the knife It 18 convertical sectionalview of a lawn mower emtrolled and kept in contact with therevolvbodying my invention. Fig. 2 is a plan view ing blade'for thefulllength are indicated at of,the fixed blade, showing also one of the13, and consist of steel'or equivalent elastic 5 rotary blades. stripsriveted to the blade 11 at 14 and bear- 45 Referring to the drawings: 1indicates one ing at their free ends 15 upon a suitablepart .of the sideframes or castings of the mower, of the frame or other equivalent stops.In the 2 a cross bar connecting the side'frames, 3 constructionillustrated the stops: for the one of the ground wheels, 4 the revolvingsprings are formed, one at each side of the ma cutter cylinder or reeljournaled in the side machine, byscrews 16 mounted in the frame. I 5frames and actuated from the ground wheels. By turning these screws theproper tension by gearing in a well known manner, and 5maybeindependentlyimpartedtothesprings. the ground roller adj ustablymounted tont he' jThese screws may however be dispensed with;

blade (so called in distinction from thereof and for the fulllength ofthe latter, and 75 y it is insured that the A blade having tlnsorearwardly extending springs 13 is adapted to be applied to a mower ofordinary construction and have the said springs bear properly againstthe mower frame, as indicated in the drawings.

It remains to describe the means by which revolving knives, which areshown at 17, shall run smoothly onto the edge of the fixed knife bladewithout abrupt shock or jar which wouldchcck the revolution of the knifeand thus add greatly to the labor of propelling the machine. 18indicates a forward extension whiehis part of or fixed to the blade 11.It is situated at that end of the blade which, by reason of the helicalshape of the revolving tered by the latter. This extension is preferablyof the contour seen in Fig. 1, slightly curved or eoncaved on its upperface at 19 to approximate the path of the revolving blade and cause thelatter to encounter the extension with the least abruptness and whenmoving almost parallel with the blades surface. At its extremity theextension is so situated that if momentarily no revolving blade isacting on the fixed blade, and the shoulder 20 of the bar 6 is incontact with the screw 8, it will nevertheless be beyond or outside ofthe path of the edges of the revolving blades. If the screw 8 is notused, and the rear end of the preceding blade serves as the stop, theextension will be of such length that it will be outside of the saidpath and ready to receive the advancing blade at the time when the rearend of the preceding blade is on the last portion of the fixed blade. Bythe use of this extension the revolving blade is guided in the mostcertain manner upon the fixed blade, without the necessity for niceadjustment of the parts, and pressure to turn the bar 6 with its knifeis first applied at a considerable distance from the pivots 7. In otherwords the fixed blade may accommodate itself gradually to the revolvingblade during the interval which the latter is moving along the extensioninstead of all at once at the instant the edges of the blades areopposite each other. By giving sufficient twist to the revolving bladesthe forward end of one blade may be caused to encounter the extension 18before the rear end of the preceding blade has left the edge of thefixed blade, as already mentioned, thereby requiring less movement ofthe fixed blade as it changes from one knife to the other. In this casethe end of the fixed blades, is first encounblade which is opposite tothat on which is the extension 18, and which is last in contact with therevolving blade, may be set slightly in advance of the end having theextension (see dotted lines in Fig. 2) thus increasing the force ofcontact between the blades at or near the end of their cut andpreventing the succeeding knife from separating, byits contact with theextension, the other end of the fixed blade from the rear portion of thepreceding revolving knife.

It will be understood that the blade as shown in Fig. 2 may bemanufactured and sold for an attachment to the fixed knife bar of manylawn mowers already in use or on the market, it being a matter of littledifliculty to substitute this blade for the ordinary fixed blade, at thesame time releasing the ordinary pivoted and adjustable knife bar sothat it may have free oscillatory movement.

Having thus described my invention, what I claim is 1. In a lawn mowerthe combination with' the revolving knife or knives, and their actuatingmechanism, of a yielding fixed knife having at one end a forwardextension to receive the edge of the revolving knife, substantially asset forth.

2. The combination with the revolving knives, of a fixed knife having atone end the extension 18, and having the other end set in advance of thefirst mentioned end and springs for pressing the fixed knife toward thepath of the revolving knives, substantially as set forth.

3. In a lawn mower the combination with the revolving knife, of anoscillating fixed.

knife having the rearwardly extending springs 13 attached thereto andadapted to hear at their extreme rear ends against the rear portion ofthe mower frame, whereby said knife may be used as an attachment withthe ordinary form of mower frame, substan-' tially as set forth.

4. As an attachment for the fixed knife bar of lawn mowers the hereindescribed blade having the extension 18 and springs 13, substantially asset forth.

In testimony whereof I ailix my signature in the presence of twowitnesses.

EDWARD R. s'rAnLER.

Witnesses:

EDWARD PEIRCE, W. II. GILPIN.

